Mis à jour : 13 mars 2019
Mistletoe belongs to a rather large and complicated family. In the plant world, parasitism had only evolved nine times and of these the plants that make up mistletoe have evolved independently five times creating families Misodenraceae, Loranthaceae, Santalaceae and, to complicate things here, the modern family Santalacea contains the old Viscaceae and Ermolepidaceae.
Our Mistletoe, common European Mistletoe, Viscum album (pictured left) belongs to the family Santalacea, and is the only species native to the United Kingdom. There are a number of sub. species belonging to the species Viscum, including Viscum album subsp. austriacum, with yellow fruits preferring larix and pines as its host. It is uncertain where the name mistletoe came from but many think it comes from the German mist, for dung and tang for branch. This could be due to it being spread in bird droppings as they move from tree to tree. If you have ever read old English herbals, which I have written about before, or really old cook books, you will have heard of mistel. This is the old English for Basil and not mistletoe, which is not edible and will give you a rather unpleasant bout of diarrhoea and a low pulse if digested.
Our mistletoe is unmistakable with long broadly ovate green leaves always occurring opposite each other, fairly brittle woody stems and clusters of up to six waxy white berries.
European mistletoe grows on a fairly broad range of host trees but it is particularly fond of old orchards in the English countryside. Lost to parts of the South Coast it is particularly prevalent in the rolling Herefordshire landscape. Mistletoe has developed a form of hemi-parasites, which means that in most species it develops evergreen leaves, which are able to photosynthesis therefore using the host predominantly for water and mineral nutrients only. In most cases, it will only reduce the vigour of its host shrub or tree, but with heavy infestation this removal of resources from the host can kill it.
In such a large family there are some odd exceptions such as the Cactus Mistletoe, Tristerix aphyllus, (pictured right), which is native to the Andes, Chile and Columbia and lives deep inside the vascular tissues of its hosts appearing only to flower with rich red flowers once a year. Before rushing out to the Garden Centre with a renewed interest in Rhipsalis baccifera, it is not this plant, although this was brought from the New World as a Mistletoe substitute.
In Europe, Mistletoe is generally spread by the Mistle Trush and is a source of food to many grazing animals, which help transfer pollen between species.
In The United States and Northern America, the genus Arceuthobium manufactures considerably less sugars than it needs and lives off its host much more. It is a dwarf species and makes tight witches' brooms, which in turn become roosting and nesting locations for Northern Spotted Owls and Marbled Murrelets. Arceuthobium is made up of 42 species with 21 being native to the United States. Unlike European Mistletoe, its host of choice are pines and cypress. Arceuthobium abietinum (pictured above) is dioecious, meaning it is individually male or female. Uniquely, following fertilisation hydrostatic pressure builds internally when ripe, shooting single sticky seeds up to 50 miles per hour into the forest. The seed is covered in a glue like substance, viscin, which enables the seed to stick and develop on its host.
The smallest known mistletoe species A. minutissimum lives only on Pinus wallichiana, a stunning, afghan hound-like pine, both native to the Himalayas.
(Photo: A. minutissimum)
The Mistletoe most Americans will be familiar with and which is grown as a harvestable crop for Christmas decorations is Phoradendron flavescens. Known as the Eastern Mistletoe, this has shorter broader leaves and longer clusters of up to 10 berries. Phoradenderon is in the family Santalaceae, like our own, but has more than 35 species.
(Photo: Phoradendron flavescens)
One I particularly like and it’s not for purists, is Phoradendron californicum, the mesquite mistletoe. Native as the name suggests to Southern California, it grows in the Mojave and Sonoran Deserts under 4000ft. It's a leafless species, which sends out tiny, heavenly fragranced flowers in winter, which are followed on the female plant by beautiful berries in shades of copper, garnet and dusky pink.
Oddly, the number of mistletoe species are much larger in the Subtropical and Tropical climates with 85 species in Australia and 900 genera in the family Loranthaceae.
Now not much more need be said of mistletoe and Christmas, our traditions of keeping some in the house from December through the year for good luck is largely unheard of in Europe. We are all agreed, however, that it is the last of the Christmas Greens to be removed from the house after Candlemas, so it remains for 40 days as stated in the Torah.
The other tradition we all take up, some not knowing its full history, is the kissing. This comes from Scandinavian Mythology. Baldr was a god who was associated with light, beauty, love and happiness. His mother Frigg, prompted by a prophetic dream, made every plant, animal and inanimate object promise not to harm him.
But Frigga overlooked the mistletoe plant — and the mischievous god Loki took advantage of this oversight, tricking the blind god Hoor into killing Baldr with a spear fashioned from mistletoe. Baldr's death brought winter into the world, until the gods restored him to life. Frigga declared the mistletoe sacred, ordering that from now on it should bring love rather than death into the world. Happily complying with Frigga's wishes, any two people passing under the plant from now on would celebrate Baldr's resurrection by kissing under the mistletoe.
Frigg herself has some lovely associations, such as Galium verum, known as Frigg's Grass. Frigg was associated with married woman and Scandinavians used this grass due to its sedative qualities during childbirth.